The second International Workshop on Social Computing, Behavioral Modeling, and Prediction (SBP'09) is scheduled to be held in Phoenix, Arizona on March 31 and April 1, 2009. This workshop was preceded by a very successful first event (SBP'08, http://www.public.asu.edu/~huanliu/sbp08) on April 1 and 2, 2008. The organizing committee was extremely encouraged by high attendance, lively discussion, and strong interest at SBP'08. The SBP'08 proceedings received excellent response during SBP'08 and afterwards, which can be found at Amazon. Based on the positive feedback from the attendees and a pressing need for a continued platform for this emerging and interdisciplinary field, the organizing committee decided to extend the success and organize a second workshop. The new workshop website is at http://www.public.asu.edu/~huanliu/sbp09. Public Health Relevance: Project Narrative Social computing is concerned with the study of social behavior and social context based on computational systems. Behavioral modeling reproduces the social behavior, and allows for experimenting, scenario planning, and deep understanding of behavior, patterns, and potential outcomes. The pervasive use of computer and Internet technologies provides an unprecedented environment of various social activities. Social computing facilitates behavioral modeling in model building, analysis, pattern mining, and prediction. Numerous interdisciplinary and interdependent systems are created and used to represent the various social and physical systems for investigating the interactions between groups, communities, or nation-states. This requires joint efforts to take advantage of the state-of-the-art research from multiple disciplines, social computing, and behavioral modeling in order to document lessons learned and develop novel theories, experiments, and methodologies in terms of social, physical, psychological, and governmental mechanisms. The goal is to enable us to experiment, create, and recreate an operational environment with a better understanding of the contributions from each individual discipline, forging joint interdisciplinary efforts. To achieve these goals and to promote this emerging area, a platform is necessitated wherein researchers can disseminate and discuss the results from related research in this area. Such a platform can help promote the growth of this high-impact research topic.